Cross cuts of a conventional ink donor sheet are shown in FIGS. 1 and 2. The sheet consists of a base 1 made of capacitor paper or polyester film and a heat-fusible ink layer 2 formed on the base. The ink layer 2 is selectively heated with a thermal head or other suitable heating means and the fused area is transferred onto the adjacent recording sheet (not shown). In the conventional ink donor sheet, the heated part of ink layer 2 is entirely transferred to the recording sheet as shown in FIG. 2, so the nature of recording is "all or nothing" and halftone reproduction is impracticable.